Created on 2017-04-28.00:00:00, last changed 2017-04-28.00:00:00.
According to 8.2.2 [expr.call] paragraph 9,
If the argument has integral or enumeration type that is subject to the integral promotions (7.6 [conv.prom]), or a floating-point type that is subject to the floating-point promotion (7.7 [conv.fpprom]), the value of the argument is converted to the promoted type before the call. These promotions are referred to as the default argument promotions.
A scoped enumeration with an underlying type that is shorter than int will not be widened when passed to an ellipsis. Should it be?